The present invention relates to a damper for modulating the flow of air through room air ducts in a building ventilation system.
With more particularity, this invention relates to a damper having an aerodynamic gasketless damper blade that provides for a tight metal to metal seal and for constant torque to accomplish stable damper operation at high airflow velocities.
Comfort quality is a common problem in buildings such as those having offices in which only one thermostat is used to control the temperature in several different rooms or spaces. Individuals in sunny rooms may often be too hot while individuals in shaded or windowless rooms are often too cold. The lack of responsiveness of such previous "single zone" building heating ventilation and air conditioning systems to different temperature needs in different discrete spaces is the major failure of such systems.
Buildings in which such single zone systems are found are typically designed with cost in mind. Solutions to the comfort problems associated with single zone systems include the conversion of existing single zone systems to a variable air volume (VAV) system or the installation of a variable air volume heating, ventilating and air conditioning system in the first instance. However, VAV systems employ equipment and controls which are often too costly to allow for their installation in the first instance and conversion to VAV systems can likewise be expensive. As a result, buildings with constant volume heating, ventilating and air conditioning systems are very common and although such systems cost less, they do not provide the comfort and performance of a VAV system with respect to discrete spaces having differing comfort conditioning needs.
The need continues to exist for building heating. ventilating and air conditioning systems and components which offer VAV performance, control and comfort yet which at least to some extent employ less expensive constant volume heating, ventilating and air conditioning equipment. Among the needs of a system offering VAV comfort but otherwise employing less costly single zone heating. ventilating and air conditioning equipment is an airflow modulating damper which, among other things, is quiet, provides a tight mechanical seal with low leakage and which does not employ discrete gasketing or seals which are capable of becoming loose or worn with time.